Context-Based Interface Prototyping: Understanding the Effect of Prototype Representation on User Feedback

Abstract

The rise of autonomous systems in cities, such as automated vehicles (AVs), requires new approaches for prototyping and evaluating how people interact with those systems through context-based user interfaces, such as external human-machine interfaces (eHMIs). In this paper, we present a comparative study of three prototype representations (real-world VR, computer-generated VR, real-world video) of an eHMI in a mixed-methods study with 42 participants. Quantitative results show that while the real-world VR representation results in higher sense of presence, no significant differences in user experience and trust towards the AV itself were found. However, interview data shows that participants focused on different experiential and perceptual aspects in each of the prototype representations. These differences are linked to spatial awareness and perceived realism of the AV behaviour and its context, affecting in turn how participants assess trust and the eHMI. The paper offers guidelines for prototyping and evaluating context-based interfaces through simulations. CCS CONCEPTS• Human-centered computing → HCI design and evaluation methods.

External communication of automated shuttles: Results, experiences, and lessons learned from three European long-term research projects

“…Due to the challenging nature of designing and assessing eHMIs in real traffic, research in this particular area is still rather scarce ( Colley and Rukzio, 2020 ; Dey et al, 2020a ). Most eHMI research has been conducted in, for example, Colley et al (2020 ); Dey et al (2021 ); Faas et al (2021 ); and Mahadevan et al (2018 ) and about various forms of simulated traffic so far (e.g., Hoggenmüller et al, 2021 ), but studies in real traffic contexts are still scarce.…”

Non-human Personas. Including Nature in the Participatory Design of Smart Cities

“…The framework was then iteratively refined through discussions with all authors, bringing in two additional external perspectives. Importantly, the two additional authors had previous experience with non-human personas [65,66] and more-than-human perspectives in the participatory design of smart cities [67,68]. We further drew on our experience with middle-out design as an approach for bring together representatives from topdown and bottom-up organisations in community engagement [69], integrating this approach into the framework as a way to form a coalition that is able to speak on behalf of non-human living beings.…”

“…A key outcome from these participatory sessions is the collective development of a descriptive narrative of the behaviour of the identified non-human persona. These narrative descriptions provide rich data that bring the persona to life [51,52], ideally through a vivid story concerning the needs of the persona in the context of the design intervention [67,68]. It is possible that during this step a persona is split into multiple representations if unique characteristics and behaviours are identified, Interaction Design and Architecture(s) Journal -IxD&A, N. 50, 2021, pp.…”

“…Fitting up to two people, the AV prototype was designed function as a shared pod to transport people between the nearby train station and the university campus and around the university campus, which sits across two Sydney suburbs. As interaction designers, we focused on devising a lowresolution lighting display serving as external human-machine interface to communicate the vehicle's intent and awareness to nearby pedestrians and riders [68].…”

“…5. Two smart city research projects were used to demonstrate the retrospective application of the non-human personas framework: Shared autonomous pod (left)[67,68] and the CiViC dashboard (right)[91].…”